Blogiartikkelit Kristian Karlsson Ilmasto, Metsä, Ympäristö

The areas with productive African woodlands are still decreasing. Logging for charcoal is one major reason for deforestation. Frequent and intensive fires prevent forest regeneration. Researchers visiting dry tropical regions may be stunned by the magnitude of the problems they face.

Smoke is a frequent view in Tanzanian woodlands. Photo: Kristian Karlsson.

I am one of many Finnish forest researchers who have been working in eastern Africa. Last year, I was travelling for two weeks in one of the provinces in Mozambique. We were driving into some relatively remote areas. Burning wood lots and recently cleared agricultural cultivations were common even far away from villages and permanent settlements. There was smoke everywhere.

According to data interpreted from remote sensing, these areas were still forests, woodlands with canopy coverage. But in reality, the countdown had started and the forest was disappearing gradually. The species composition was changing partly due to selective harvesting of individual trees, but also as a result of the difference in fire tolerance among species.

There was no regeneration of actual forest trees. Some of the older logged and cleared areas had turned into bushland and thicket, woody vegetation which indicates a lowered productivity of the soils. The local researchers did not react heavily on what we saw. They had seen it all before.

The traditional way is to “cultivate with fire”, so vegetation is burnt regularly. Some well-known African ecologists have also emphasized the benefits of forest fires in the natural development of these miombo woodlands.

I think that the good effects are restricted to natural state woodlands, where only a small amount of “fuel” is present on the forest floor, and the wild fires are burning the surface very lightly. The conditions will start to change with the first selective logging.

The traditional way is to “cultivate with fire”.

Other factors are involved, too. The frequency and the intensity of all fires have increased as the climate change has introduced pronounced drought spells in most dry tropical regions. It seems almost impossible to maintain forest utilization at a sustainable level if the fires cannot be limited.

Changing the charcoal trade?

Almost 200 tons of charcoal is transported to Dar es Salaam every day. Photo: Kristian Karsson.

It takes at least four hours to drive by car from the big city of Dar es Salaam to Morogoro in Tanzania. That’s where most of the forest researchers are working. The trip gives you plenty of time to speculate on forest change. The woodlands outside Dar es Salaam do not exist anymore – they were cut down a long time ago. It’s just open vegetation now.

Our Tanzanian colleagues have estimated the effects of charcoal utilization, which most likely has caused the woodlands to disappear. Most people in the city still use charcoal for cooking and heating water. A single bag of charcoal weighs 50–60 kg, and about 30,000 bags are transported to Dar es Salaam every day.

Providing this amount of charcoal to the citizens would require an annual clear cut of about 110,000 hectares. Producing the same amount of charcoal with sustainable harvesting of natural forests would take a production area of 1.5 million hectares. Thus, it is not so surprising, that the FAO has listed charcoal production as a major cause for the loss of woodlands in Tanzania.

Charcoal is an extreme example of low-value end-products. It is sold everywhere along the roads and markets, where the price is counted in shillings per bucket. Convert those shillings into euros, and it’s close to nothing. With a better price for forest end-products, it would be easier to introduce more effective methods and raise the level of silviculture.

With a better price for forest end-products, it would be easier to introduce more effective methods and raise the level of silviculture.

An attempt was made in the international markets to buy and sell “Carbon Credits”, a compensation for carbon maintained in growing stock instead of cutting and selling wood. In the beginning, this “product” was highly priced at 40 USD per ton of carbon dioxide. So, theoretically, you would earn one credit for each m3 of wood you produce and maintain.

Unfortunately, this procedure is relying completely on global markets, and it seems to have crashed (almost). The new carbon business did not work out. That leaves us, the researchers, with the task of finding or introducing more valuable products from the forestry production chain. Fortunately though, there are some real opportunities there, too.

Meeting the challenges

An enormous amount of carbon dioxide is released from those two activities: burning vegetation in the woodlands on one hand, and burning wood for charcoal on the other. The consequences are often devastating locally, and there is a connection to global climate change. Many of the issues are relatively well known, and it is easy to make a list of things where research can provide solutions.

However, it’s much more difficult to select the most important topics – those that can give reasonable results within the given timeframe, and the ones that will have real effects on the environment and for the local communities.

One of the advisors for our project in Mozambique recently quoted a statement made by the World Bank:

”…detailed information on forest composition, growth and yield in the various miombo forest types in Mozambique is not existent or easily accessible. Even less is known about the effect of silvicultural interventions such as thinning, enrichment planting and management of regeneration. Accordingly, some funding should be channeled into applied research, e.g. in partnership with research institutions and forest concessionaires. Research could, for example, be linked to periodic inventories for forest management planning as well as pre- and post-harvest inventories. However, the lack of science-based information on miombo forest dynamics shouldn’t prevent starting immediately with the implementation of responsible silviculture.”

I think that quotation is really good advice for all of us working in this field.



  1. What are the valuable products from the forestry production chain in Mozambique? What are the alternatives for people living in the city for cooking and heating water instead of using charcoal? How to discourage the traditional way of “cultivating with fire”?


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